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Book of 99 Slot Review: A Guide to an Exciting Greek-Themed Slot



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Get ready to reach the very heart of ancient Greek mysticism, as our exclusive Book of 99 slot review will show you the innermost secrets of Greek mythology. We’ll not only judge this book by its cover but also read every note in it and share it with you.

Therefore, opening a new book or turning over a new leaf may be a cool idea with this very interesting high RTP slot game.

book of 99 video slot home screen

Book of 99 Slot Features: What Makes This Game So Popular

Looking at the title, anyone could say that this is yet another “book of” game. But guess what, it’s not. With a high RTP rate, this game stands out from the rest of the games in this category. But wait, this game’s provider also put an additional exotic feature or two to make it more special.

Provider:Relax Gaming
Features:Free Spin rounds, Wilds, Expanding Symbols, Symbol Collection
Minimum Bet:0.10
Maximum Bet:100
Type of Slot:Video Slot
Slot Theme:Ancient Greece
Jackpot Type:None
Maximum Payout:X12,075 your stake amount
Bonus Round:Yes
Release Date:4 May 2021
Autoplay Option:Yes
Mobile Available:Yes

Exploring the Benefits of Book of 99 Slot

Reading a book is the window to another world, right? Well, that’s exactly how we felt about this game. It’s not only its interesting theme that made us feel that way but also some unique things that bring moments to remember.

High Book of 99 RTP rate.

The return rate of this game is a pure rarity

Collection meter feature

Valuing long-term players

Few ways to trigger the Book of 99 bonus rounds

As few as two or three match symbols could be Book of 99 bonus triggers

Interesting wild symbols

Expanding wilds that could cover the entire reel


RTP is an average pay-out measure, always below 100%, reflecting the house’s advantage. It doesn’t guarantee wins as they depend on luck and chance. RTP is subject to change, so always visit the official operator’s website for the latest information.

Best Places to Play Book of 99 With Real Funds

Even though the Book of 99 volatility rate in other games is rare, the platforms you can find this game on are not. In fact, we have singled out some of the Book of 99 best casinos in UK you can have a pleasant experience with.

Top Pick by Our Editors
Casumo Casino
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      Top Pick by Our Editors
      50 FREE SPINS & up to £100
          18+,, Full T&Cs apply.. New reg only. Opt in & deposit either £10, £25 or £50 within 7 days & further 7 days to wager your deposit 35x to unlock reward (up to £50 for each of your first 2 deposits). Wagering/game contributions vary. 25 x 10p wager-free spins added to Big Bass Splash with each qualifying deposit, 3 day expiry. Other Promotional Play Restrictions Apply. T&Cs apply.
          No Operators Found
          Amazon Slots
              New players only, £10 min fund, Free spins won via mega reel, 65x bonus wagering requirements, max bonus conversion to real funds equal to lifetime deposits (up to £250), T&Cs apply

              Book of 99 Overview: The Cover and The Pages in One Place

              Just as we glanced at the interface, we saw somewhat interesting colours and symbols. And as soon as we had our first spin, we saw how interesting the Book of 99 gameplay was.

              With different-value symbols that are made with special care in terms of graphics, going from one chapter of the Book of 99 into another was something that didn’t leave us disappointed. The simplicity that comes behind the gameplay was also another thing we could make use of.

              The overall reel and grid organisation also go well with the potentially landing wild symbols. The free spins bonus rounds are also interesting as they offer additional playing options. Moreover, the expanding wilds, some of which can cover the entire reel and be able to combine in different directions, are definitely a “yes” for us.

              Book of 99 Gameplay: Going From One Chapter to Another

              The combination of mythological symbol creatures and standard symbols created a sort of unique atmosphere. What we mean here is that we expected high-value symbols to appear but were low-key kind of in awe due to the connotations of cyclops and scary ladies.

              The easy-to-use spin button, a well-positioned button to increase the speed of symbols landing, and a button to turn on the autoplay are probably the things that you’ll use most here.

              In addition, you can press the button on the far right and set your stake amount. The button on the far left gives you an overall view of the game rules, including symbol value. As mentioned, the landing symbols could go faster or slower depending on your preferences.

              When you click on the auto spin button, it asks about the number of rounds you want this option to last. The collection feature is placed above the reels, with the number 0 changing into 1 or higher and moving from left to right, hence leading you to the free spin round.

              book of 99 gameplay

              Book of 99 Graphic and Sound

              As our Book of 99 slot review said, the dark-coloured slot theme predominates this game’s graphics. The first thing showing you this is the background with purplish clouds and greenish mountains.

              The greystone temple with the bank that’s occasionally hit by the waves only adds to the sinister atmosphere. The general colourisation of the game is also low, which further increases the Dracula-like ambient.

              You’ll see that the number and letter symbols have a gem inside. There’s a barely noticeable circle around each letter and number symbol. The creature symbols are squared, and all of them look a bit spooky.

              The sounds in this game are made to depict a somewhat creepy atmosphere and the mysticism of ancient Greece. There’s solemn background music and sound effects that appear once symbols combine.

              Book of 99 Payout table (Paylines)

              The Book of 99 payout table is diversified, where every symbol has its own value. Generally speaking, there are lower-paying symbols (letters and a number) and higher-paying symbols (creatures and other characters).

              Symbol TypeBook of 99 Payout Table Value
              Book symbolThis symbol can take the place of any other symbol except for the expanding symbols.
              The man in the red background5 – 5004 – 1003 – 10
              The lady with a purple shawl5 – 2004 – 403 – 4
              A Cyclop5 – 754 – 103 – 32 – 0.50
              Letters A and K5 – 154 – 43 – 32- 0.50
              Letters Q and J5 – 104 – 2.503 – 0.50
              Number 105 – 754 – 153 – 4
              book of 99 paylines

              Book of 99 Symbols

              Your gameplay can be very diverse, with some creepy but high-paying symbols, along with some classic letters and a number, all the way to the book wild symbols. Furthermore, any standard symbol can become an expanding one during the free spin rounds. Let’s check what this is exactly all about.

              Book of 99 Bonuses & Free Spins

              In spite of there not being features like the Book of 99 jackpot wheel, this game comes with certain free spin rounds. First of all, a minimum of two low-paying and three high-paying symbols should combine in order for them to result in any winnings.

              Speaking of the Book of 99 bonus triggers, it’s the book symbol that should appear in line at least three times. Once this happens, players will enter into a free spin round, during which they can use 10 free spins.

              While Book of 99 bonus rounds are ongoing, one of the standard symbols that the wild symbol replaced before the round started becomes special. Every time that symbol appears, it expands and creates more opportunities for symbols to combine.

              Expanding symbols are the real bookbinders here. More precisely, such a symbol can, in some instances, cover the entire reel or pay all 10 lines. The expanding symbol does not need to be directly lined with other paying symbols in order to combine.

              As far as the top win goes, it depends on the symbol that initially became expanding before the free spin round was triggered. The possible win range can go from x100 to x5000.

              Not only that, but another three wilds can also land and trigger another free spin round. That being said, it’s obvious that there’s no limit as to how many free spin rounds you can be part of.

              Book of 99 RTP and Volatility

              Our Book of 99 slot review has said it once, but will point out that again – the RTP rate of this game is as high as 99%. While the majority of slots’ RTP rate is around 90%, and some of them can hardly reach 95%-96%, this game surely stands out.

              Similarly, the Book of 99 volatility rate is also high. With such high rates, your experience as a player will not be just another ordinary process of repeatedly bashing the spin button.

              Book of 99 Mobile Compatibility

              Relax Gaming spent a lot of time optimising this game and making it shine on a mobile platform, too. After seeing it run on a mobile phone, our Book of 99 slot review realised that this game works very smoothly. It’s important to note that there’s no separate Book of 99 mobile slot app.

              However, no slot app is really needed when you can find this game on some of the Book of 99 best casinos. All in all, the bits and pieces of this game that you can experience on a desktop website can also be experienced while playing the Book of 99 mobile slot game.

              book of 99 video slot home screen

              Book of 99 Pros & Cons

              When put side by side, there are more pros than cons to this. Still, our complete and unbiased slot review contains some examples on both sides.

              Pros Cons
              High RTP rate No jackpots, so there is no Book of 99 Jackpot wheel option
              Wild symbols that act as game-changers
              Free spin rounds
              Simple design and easy to play

              Why We Rated Book of 99 as Excellent (4.8)

              Testing out this game was very interesting for our Book of 99 slot review. But rating it as excellent was a special pleasure, as this is the real “what you see is what you get” situation. The Book of 99 slot machine game deserved every star (4.8) we gave it.

              1. 1. Special horror-like theme.
              2. 2. Great wild symbols that largely affect the overall symbol combination.
              3. 3. High RTP rate.
              4. 4. Low minimum and high maximum stake amount.
              5. 5. Special features, such as the collection meter.

              Book of 99 Slot Conclusion

              If we were to look for a more interesting “book of” games, we highly doubt that we could find one. The game has all that an ordinary slot from this category should possess. Yet, its RTP rate of 99% was paralleled with its name, the Book of 99 online slot.

              A high RTP rate is something that many users look for in a slot game. But it’s not only about the RTP rate here. The game boasts unique graphics and sounds related to its spooky ancient Greek theme. Plus, the Book of 99 mobile compatibility is pretty good.

              Wild and other high-paying symbols are there to bring the gameplay to another level with different directions in combinations. Plus, the free spin rounds they can trigger are synonymous with experiencing interesting moments.

              Which Slots are Similar to Book of 99?

              The amount of “book of” games is high. While no game can include exactly the same features, you can also look up similar ones in case you want to play a sister game to Book of 99.

              Book of 99: FAQ

              Our Book of 99 slot review concludes with the FAQ section, where we provide you with an overall set of quick questions and answers containing some Book of 99 tips and tricks.

              The theme of the Book of 99 slot is ancient Greece. In fact, it’s more like a horror-type game with symbols from this era.

              The bonus rounds in this game are actually the free spin rounds. While they’re ongoing, you can use 10 free spins, as well as having expanding wilds land on the reels and increase the potential number of symbol combinations. Every wild symbol that lands during a regular round can also be collected and will later serve a free spin round trigger.

              The RTP rate of this game is 99%. This is the game with one of the highest RTP rates out there.

              The Book of 99 is a volatile game. Even more, its volatility rate is pretty high.

              While there’s no Book of 99 mobile app, you can find a mobile version of this game on any brand’s website that lists this game as available on its desktop site, too. The Book of 99 mobile slot game is as functional as its desktop version.

              There are plenty of websites that will let you engage in the Book of 99 slot demo play activities. Of course, even this version is available only to players of legal age.

              Apart from the Book of 99 slot demo play, the most popular version of this game is the one you can play for real funds. That being said, you can explore our website and find many great brands on whose site you can play this game in UK.

              The maximum payout for this game is the x12,075 your stake amount.  This further means that the symbol combination opportunities, along with bonus features in this game, are numerous.

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